<template>
  <div class="goods">
    <div class="menu-wrapper" v-el:menu-wrapper>
      <ul>
        <li v-for="item in goods" class="menu-item" :class="{'current':currentIndex === $index}"  @click="selectMenu($index,$event)">
          <span class="text border-1px">
            <span class="icon" v-show="item.type>0" :class="classMap[item.type]"></span>
            <span>{{item.name}}</span>
          </span>
        </li>
      </ul>
    </div>
    <div class="foods-wrapper" v-el:foods-wrapper>
      <ul>
        <li v-for="item in goods" class="food-list food-list-hook">
          <h1 class="title">{{item.name}}</h1>
          <ul>
            <li v-for="food in item.foods" class="food-item border-1px" @click="selectFood(food,$event)">
              <div class="icon">
                <img :src="food.icon" width="57" height="57">
              </div>
              <div class="content">
                <h2 class="name">{{food.name}}</h2>
                <p class="desc">{{food.description}}</p>
                <div class="extra">
                  <span class="count">月售{{food.sellCount}}份</span>
                  <span>好评率{{food.rating}}%</span>
                </div>
                <div class="price">
                  <span  class="now">￥{{food.price}}</span>
                  <span  class="old" v-show="food.oldPrice">{{food.oldPrice}}</span>
                </div>
                <div class="cartcontrol-wrappe">
                  <cartcontrol :food="food"></cartcontrol>
                </div>
              </div>
            </li>
          </ul>
        </li>
      </ul>
    </div>
    <shopcart  v-ref:shopcart :delivery-price="seller.deliveryPrice" :min-price="seller.minPrice" :select-foods="selectFoods"></shopcart>
  </div>
  <food :food="selectedFood" v-ref:food></food>
</template>

<script>
  import BScroll from 'better-scroll'
  import shopcart from '../shopcart/shopcart.vue'
  import cartcontrol from '../cartcontrol/cartcontrol'
  import food from '../food/food.vue'

  const ERR_OK = 0
  export default {
    props: {
      seller: {
        type: Object
      }
    },
    data () {
      return {
        goods: [],
        listHeight: [],
        scrollY: 0,
        selectedFood: {}
      }
    },
    created () {
      this.classMap = ['decrease', 'discount', 'special', 'invoice', 'guarantee']
      this.$http.get('/api/goods').then((response) => {
        response = response.body
        if (response.errno === ERR_OK) {
          this.goods = response.data
          this.$nextTick(() => {
            this._initScroll()
            this._caculateHeight()
          })
        }
      })
    },
    computed: {
      currentIndex () {
        for (let i = 0; i < this.listHeight.length; i++) {
          let height1 = this.listHeight[i]
          let height2 = this.listHeight[i + 1]
          if (!height2 || (this.scrollY >= height1 && this.scrollY < height2)) {
            return i
          }
        }
        return 0
      },
      selectFoods () {
        let foods = []
        this.goods.forEach((good) => {
          good.foods.forEach((food) => {
            if (food.count) {
              foods.push(food)
            }
          })
        })
        return foods
      }
    },
    methods: {
      selectMenu (index, event) {
        if (!event._constructed) {
          return  //  这是better-scroll派发的属性 要是不是的话就return 防止pc二次点击。event._constructed存在时，则为自己派发的属性
        }
        let foodList = this.$els.foodsWrapper.getElementsByClassName('food-list-hook')
        let el = foodList[index]
        this.foodsScroll.scrollToElement(el, 300)
      },
      selectFood (food, event) {
        if (!event._constructed) {
          return  //  这是better-scroll派发的属性 要是不是的话就return 防止pc二次点击。event._constructed存在时，则为自己派发的属性
        }
        this.selectedFood = food
        this.$refs.food.show()
      },
      _initScroll () {
        this.menuScroll = new BScroll(this.$els.menuWrapper, {
          click: true //  better-scroll会阻止click的默认行为 这里自己派发一个点击事件
        })
        this.foodsScroll = new BScroll(this.$els.foodsWrapper, {
          click: true,
          probeType: 3  //  能实时获取到滚动的位置
        })
        this.foodsScroll.on('scroll', (pos) => {
          this.scrollY = Math.abs(Math.round(pos.y))
        })
      },
      _caculateHeight () {
        let foodList = this.$els.foodsWrapper.getElementsByClassName('food-list-hook')
        let height = 0
        this.listHeight.push(height)
        for (var i = 0; i < foodList.length; i++) {
          let item = foodList[i]
          height += item.clientHeight
          this.listHeight.push(height)
        }
      },
      _drop (target) {
        // 访问子组件shopcart 调用子组件的shopcart方法
        // 体验优化，异步执行下落动画
        this.$nextTick(() => {
          this.$refs.shopcart.drop(target)
        })
      }
    },
    components: {
      shopcart,
      cartcontrol,
      food
    },
    // 接收事件
    events: {
      'cart.add' (target) {
        this._drop(target)
      }
    }
  }
</script>

<style lang="stylus" rel="stylesheet/stylus">
@import '../../common/styls/mixin'
  .goods
    display flex
    overflow hidden
    position absolute
    top 174px
    bottom 46px
    width 100%
    .menu-wrapper
      flex 0 0 80px 
      width 80px
      background #f3f5f7
      .menu-item
        display table
        width 56px
        height 54px
        line-height 14px
        padding 0 12px
        &.current
          position relative
          margin-top -1px 
          z-index 10
          background #ffffff
          font-weight bold
          .text
              border-none()
        .icon
          display inline-block
          vertical-align top
          width 12px
          height 12px
          margin-right 2px
          background-size 12px 12px
          background-repeat no-repeat 
          &.decrease
            bg-image('decrease_3')
          &.discount
            bg-image('discount_3')
          &.guarantee
            bg-image('guarantee_3')
          &.invoice
            bg-image('invoice_3')
          &.special
            bg-image('special_3')
        .text
          display table-cell
          font-size 12px
          width 56px 
          vertical-align middle
          border-1px(rgba(7, 17, 27, 0.1))
    .foods-wrapper
      flex 1
      .title
        padding-left 14px 
        height 26px
        line-height 26px
        border-left 2px solid #d9dde1
        font-size 12px
        color rgb(147, 153, 159)
        background #f3f5f7
      .food-item
        display flex
        margin 18px 18px 0 18px 
        padding-bottom 18px
        border-1px(rgba(7, 17, 27, 0.1))
        &:last-child
          border-none()
        .icon
          display flex
          margin-right 10px
        .content
          flex 1
          .name
            margin 2px 0 8px 0
            height 14px
            line-height 14px
            font-size 14px
            color rgb(7, 17, 27)
          .desc, .extra
            line-height 10px
            font-size 10px
            color rgb(147, 153, 159)
          .desc
            margin-bottom 8px 
            line-height 12px
          .extra
            &.count
              margin-right 12px
          .price
            font-weight 700
            line-height 24px
            .now
              color rgb(240, 20, 20)
              margin-right 8px
              font-size 14px
            .old
              font-size 10px
              color rgb(147, 153, 159)
              text-decoration line-through
          .cartcontrol-wrappe
            position absolute
            right 0
            bottom 12px 






</style>